Estimated Sulfur Dioxide Levels in Foods

≥100 ppm

Dried fruit (excluding dark raisins and prunes) Lemon juice (non-frozen) Lime juice (non-frozen) Wine Molasses Sauerkraut juice Grape juice (white, white sparkling, pink sparkling, red sparkling) Pickled cocktail onions

50 to 99.9 ppm

Dried potatoes Wine vinegar Gravies, sauces Fruit topping Maraschino cherries

10.1 to 49.9ppm

Pectin Shrimp (fresh) Corn syrup Sauerkraut Pickled peppers Pickles/relishes Corn starch Hominy Frozen potatoes Maple syrup Imported jams and jellies Fresh mushrooms

≤10 ppm

Malt vinegar Canned potatoes Beer Dry soup mix Soft drinks Instant tea Pizza dough (frozen) Pie dough Sugar (especially beet sugar) Gelatin Coconut Fresh fruit salad Domestic jams and jellies Crackers Cookies Grapes High fructose corn syrup

Note:

• The FDA banned the use of sulfites from fresh fruits and vegetables other than potatoes
  • Packaged foods containing >10ppm residual SO2 equivalents must declare the presence of sulfites on the label
  • Sulfites may be listed on food package labels as sulfur dioxide, sodium or potassium bisulfite, sodium or potassium metabisulfite, sodium sulfite
• Injectable epinephrine (EpiPen, TwinJect), injectable dexamethasone, isoprotenerol, and other drugs may contain sulfites

Diagnosis

Sulfite Challenge for Sulfite-exacerbated Asthma (Simon)

All doses should be swished for several seconds before swallowing Measure FEV1 prior to dose and if symptoms develop If the patient reacts to an active dose, then the challenge is stopped and deemed positive
Step 1 (placebo)	10 mL vehicle solution (e.g. sulfite-free lemonade) then observe 30 min
Steps 2-4	Give 10 mL vehicle containing: 10, 50, and then 100 mg potassium metabisulfite; allow 30 min between doses
Step 5 (placebo)	10 mL vehicle solution then observe 30 min

• Simon: no skin testing unless a convincing history of anaphylaxis, and a capsule challenge (maximal 200 mg single dose) is done for patients with history of urticaria or anaphylaxis

Intensive Protocol(Bush)

Testing material: potassium metabisulfite
Step 1	SPT	0.001 mg/mL 0.01 mg/mL 0.1 mg/mL 1 mg/mL
Step 2	ID testing	0.02 mL of 0.001 mg/mL solution
Step 3	Oral challenge (solution, swish/swallow)	1 mg, 10 mg, 25 mg, 50 mg, 100 mg Interval 20 min Spirometry pre/post each dose
Step 4	Oral challenge (capsule)	1 mg, 10 mg, 25 mg, 50 mg, 100 mg Interval 20 min Spirometry pre/post each dose

Management

• Avoidance of highly sulfited foods (>100 ppm) and drugs containing sulfite; very sensitive individuals may need to avoid foods containing >10 ppm (see table above)
  • Avoid all potato products in restaurants except baked potatoes with skins intact
  • Epinephrine should be used when necessary despite the fact that it may contain sulfite as a preservative
• Unproven treatments include vitamin B12, atropine, doxepin, and cromolyn sodium

Epinephrine with Metabisulfites (Lieberman)

• It is highly doubtful that the amount of metabisulfite contained in injectable epinephrine is sufficient to produce an adverse reaction even in a patient who has a history of a possible previous adverse reaction to metabisulfites.
• A metabisulfite-free preparation of epinephrine may be available for ophthalmologic use, but there have been shortages
• The following graded dose challenge approach (over 2-3 days to avoid issues due to pharmacologic effect of epinephrine) has allowed patients to take epinephrine preserved in metabisulfite:
  • 1:100,000 dilution
    • 0.1, 0.2, 0.4, 0.8 mL SC at 30 minute intervals
  • 1:10,000 dilution
    • 0.1, 0.2, 0.4, 0.8 mL SC at 30 minute intervals
  • 1:1000 (standard dilution for anaphylaxis)
    • 0.1 mL
    • If they have no problem with 0.1 mL (other than known effects of epinephrine), we deem it safe to take the 0.3 mL standard dose if they should need it

References